Too Many Moles?

Conventional wisdom has it that people with lots of moles need to be extra worried about skin cancer. A new study suggests otherwise.

If you are one of those people who have quite a few moles, you may have worried about your risk for developing melanoma, the deadliest from of skin cancer, since changes in moles are a major warning sign for this cancer. The findings of a new study from the Harvard T.H. Chan School of Public Health may ease your concerns.

It is not the number of moles you have, the researchers say, but, at least in patients under 60, the number of atypical moles you have that raises your risk for melanoma.

Use your smartphone to take photos of your moles and see if they change over time.

The researchers found that people under 60 diagnosed with melanoma tended to have more atypical moles, and their tumors were thicker (greater than 2.01 millimeters in depth). These thicker tumors were associated with a poorer outcome.

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“Several public health messages emerge from our study, including that melanomas are more commonly diagnosed in individuals with fewer moles compared with those with a high mole count,” they wrote. Physicians and patients should not rely on the total mole count as the only reason to perform skin examinations or as a method of determining a patient’s melanoma risk.

The researchers surveyed 566 patients in Michigan and California within three months of their diagnosis with melanoma. They found that among those younger than 60 years old, having more than 50 total moles was associated with a significantly reduced risk of having a melanoma greater than 2.01 mm in thickness. However, having five or more atypical moles, versus none, was associated with a far greater likelihood of thick melanoma.

The ABCDs of Melanoma
Atypical moles are defined as those exhibiting the ABCDs of melanoma: the moles were Asymmetrical, meaning they were different on one side from the other; they have an irregular Border; their Color changes from a beige or a tan to a darker brown; and their Diameter is wider than that of a pencil eraser.

No matter how many moles you have, you need to monitor them. “Melanoma is the only visible cancer. The argument we make is that everyone has to be involved: medical providers, patients and patients’ family members,” Alan Geller, the lead author on the study, told TheDoctor.

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It can be hard for people to keep an eye on all of their moles as they change. If you have moles on your back, ask your partner to help, said Geller, a senior lecturer on social and behavioral sciences at the Harvard T. H. Chan School of Public Health.

“Know your skin. Know how many moles you have,” advises Geller. Use your smartphone to take photos of your moles and see if they change over time.